Drill structure



Juiy 9, 1929, NIKOUSH I 1.720.341

DRILL STRUCTURE Filed April 9, 1928 Patented July 9, 1929.

uuiren STATES PATENT OFFICE.

MIKE NIKOLIS H, O]? WILLIAMSON, IO'WA, ASSllIGNOR 'lO AhillElL-HICAN MINING- TOOL GOYLVEPANY, OF Q'TTUMW'A, IOWA, A CORPUItA'llIO'N OF IUilVA.

DRILL ,HTRUCTURTB.

Application filed April 9, 1928.

This invention relates to improvements in drill structures conuuonly known as mole foot heads of the type particularly designed for drilling blast holes in coal veins, and it has tor one oi? its objects to provide improved means for detaclnibly securing the mole loot loose often works out of position and is lost.

Also, bending it back and forth at the split soon, breaks the cotter pin at this point andit becomes ineitlective to hold the mole i'toot head on the shaft. My improved securing means is in position at all times, is always out of the way when the head is in use, and securely keys the head to the square shank of the anger at all times when in operative position.

in the drawings,

Fig. l a plan view of my improved mole toot head mounted in position upon the square shank of an auger shalt, being partly broken away to show the means for holding the cutting bits in position;

Fig. 2 is a cross'sectional view onthe line 2-2 of Fig. l; and

Fig. 3 is a longitudinal sectional view through my improved head taken on the line 33 01 Fig. 2, and illustrating the locking key in elevation.

.rle'lerring to the drawings, 5 indicates the mole toot head or spiral auger conveyor ot the drill, which is usually provided with two spiral. or helical conveying ribs 6, which, as the drill operates, conveys the material from the opening being drilled. The head 5 is cored out longitudinally as shown at 7 to receive the square shank 8 of an auger shaft. This cored out portion of the head tapers inwardly toward its inner end so that the tapered end of the square shank 8 fits snugly therein, as shown in Fig. 3.

As shown in Fig. 1, a longitudinal slot 9 is provided in one of the helical conveying ribs 6 of sufficient width to receive a locking key 10. The locking key 10 extends longitudinally of the head and lies partly within Serial No. 268,589.

the slot 9, and is provided. with a loop 11 at one end, said loop being pivotally mounted on a pivot pin l2 which passes through the helical coi'iveying rib G at op positc sides oil? the slot 9.

The other end 13 ot the locking key 10 is bent at an angle so as to pass through an opening 14: in the head and into an opening 15 in the square shank of the auger, which opening 15 alined with the opening il/l when the parts are in operatiw position, as shown in Fig. 3. (la the opposite side from the opening jl+l the head 5 is provided with an opening 16, alined with the openings 14L and 15, through which a. suitable punch may be inserted for driving the bent end 13 of the locking key out of engagement with the opening lo in the square shank 8 oi? the aug rer, ii there any tendency for the key to lJBCOlTlt) bound against release.

It will beseen from the tli'oregoiu description that by the use Oil my improved locking key the head 5 may be quickly secured in place on the square shank 8 ot the auger. Furthermore, this locking key :anuot readily be broken, and it cannot be lost as it is always held securely in place. Also, as it lies almost entirely in the slot 9 it is not in the way to prevent the material drilled out from readily passing along toward the rear of the head between the helical conveying ribs as the device is being opm'ated.

The head 5 is provided with a plurality of cutting bits 17, and another :leature of my present invention is the improved means for removably seeming these euttin bits in position in the head. ll hilc I have shown. my device as provided with two sets of these cutting bits, one on each side of the head. with three hits in each set, it is to be understood that any number of bits may be used as desired. I shall only describe the mounting of one set of cutting hits, as the other set is similarly mounted in the head. I provide the outer end of the head with a plurality of openings 18 for each set of bits, in the construction shown three such. openings being provided, and these openii'igs extend inward.- ly and communicate with a cored out portion 19 in the head (see Fig. 1). This cored out portion 19 tapers inwardly as shown, and the heels of the bits rest on the bottom of the cored out portion of the hca d so that the sides oi? the bits contact with each other at their lower ends, shown. The wall of the head adjacent the cored out portion 19 is provided with a screw-threadedopening 20 (see Fig. 1), in which threads a set screw 21. By tightening the set screw 21 the lower ends of the cutting bits 17 are wedged tightly together and against the opposite wall 19 of the cored out portion, and are thereby held securely in place, as will be readily understood. The cutting bits have a rather loose litin the openings 18 so that the inner ends of the bits can move laterally into pressure engagement with each other under the action of the set screw 21. It will be readily apparent that by securing the bits as shown and described. they will be prevented from accidentally falling out of the head but they can be readily removed for sharpening or renewal when desired.

I claim:

1. A drill structure comprising in combination, an anger conveyor provided witha oluralit '01 helical conve ing ribs. a shaft on which said auger conveyor is mounted, and means pivotally mounted in one of said hclical conveying ribs for detachably securing said auger conveyor on said sh aft.

2. A drill structure comprising in combination, an anger conveyor provided with a plurality of helical conveying ribs, a shaft on which said auger conveyor is mounted,

' and means for detachably securing said auger auger conveyor with respect to a shaft on which it is mounted.

5. A drill structure comprising an auger conveyor provided with helical ribs having a slot disposed between said ribs, a. latch one end of which is pivoted to one 0] said ribs in juxtaposition to said slot. the other end of which is formed to project through said slot and a hole in a shaft on which the strin-ture is mounted to thereby hold the structure on the shaft.

6. A drill structure comprising an anger conveyor provided with helical ribs having a slot disposed between said ribs. an L-shapcd latch one end of which is pivoted to one of saidribs in juxtaposition to said slot, the other end of which is formed to project through said slot and a hole in a shaft on which the structure is mounted to thereby hold the structure on the shaft.

7. A drill structure comprising an auger conveyor provided with helical ribs having a slot disposed between said ribs and a second slot in one of the ribs, an L-shapcd latch having a ring -t'ormcd upon one end. said end being pivotally supported in said second slot, the other end of which is projected through said first slot and a slot in a shaft registering therewith to hold the auger conveycr on said shaft.

8. A drill structure comprising an auger conveyor provided with helical ribs having a slot disposed between said ribs, an L-shapcd latch one end of which is pivoted to one of said ribs in juxtaposition to said slot the other end of which is formed to project through said slot at one. side of said auger conveyor and into a hole in a shaft on which the structure is mounted to thereby hold the structure on the shaft, said slot at the other side of said conveyor providing for the in- 

